Tanguar Haor a large haor lies within Sunamganj district extending over 10 mauzas of Dharmapasha and Tahirpur upazilas of the district. The Tanguar Haor consists of 120 beels of various sizes. The area of Tanguar Haor including 46 villages within the haor is about 100 sq km. of which 2802.36 ha is wetland.

Tanguar Haor is an ideal place for the migratory birds. Every winter about 200 types of migratory birds come to this haor and make their temporary habitat here.

Once upon a time to make cruise into this haor with large pansi boats for hunting birds.
The haor is an important source of fisheries.

More than 140 species of fresh water fishes are available here. Among them the notables are Air, Gang, Magur, Baim< Tara Baim, Gutum, Gulsha, Tengra, Titna, Garia, Beti, Katkia etc. In the 1999-2000 fiscal year. Government earned Tk 70,73,184 as revenue only from fisheries of the haor.

Hijal (Barringtonia acutangula), Karach (Pongamia pinnata), Gulli, Balua, Ban Tulsi (ocimumamericanum), Nalkhagra (Phragmites Karka) and some other important treatened species of fresh-water wetland trees are available in this haor.

Most of the inhabitants of the Tanguar Haor are landless or marginal farmer. As the haor allows single crop throughout a year acute here. But the farmers harvest high yield because of the richness of the soil though the lands are single cropped.

In the past few decades the total environmental setting of the Tanguar haor has degraded a lot. In consideration of its environmental importance and heritage, the government has decided to save the large haor by Symbolizing it as an internationally critical environment area and listed the haor as a ‘Ramsar area’ under Ramsar convention. In accordance with this, the government has taken massive plan to restore the natural environment has taken massive plan to restore the natural environment and heritage of the Tanguar Haor by conserving its water, improving agriculture and fish production, and making the haor secured Zone for birds and animals.